Update SQLite configuration for on-disk database storage

- Add ClassVar type annotation for DB_DIR in config.py
- Add Base import in base.py for proper Alembic migrations
- Update README with detailed SQLite configuration information

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

README.md

@@ -15,7 +15,7 @@ A Todo application backend built with Python, FastAPI, and SQLAlchemy.
 - **SQLAlchemy**: SQL toolkit and ORM
 - **Alembic**: Database migration tool
 - **Pydantic**: Data validation and settings management
-- **SQLite**: Lightweight disk-based database
+- **SQLite**: Lightweight disk-based database (stored in `/storage/db/db.sqlite`)
 - **Uvicorn**: ASGI server
 
 ## Project Structure
@@ -55,12 +55,19 @@ A Todo application backend built with Python, FastAPI, and SQLAlchemy.
    ```
    alembic upgrade head
    ```
+   This will create the SQLite database file at `/storage/db/db.sqlite`
 
 4. Start the server:
    ```
    uvicorn main:app --reload
    ```
 
+### Database Configuration
+
+The application uses SQLite as its database backend. The database file is stored at `/storage/db/db.sqlite`, outside the project root directory for better data isolation. The directory is automatically created if it doesn't exist.
+
+To change the database location, modify the `DB_DIR` variable in `app/core/config.py`.
+
 ### API Documentation
 
 Once the server is running, you can access:

app/core/config.py

@@ -1,4 +1,5 @@
 from pathlib import Path
+from typing import ClassVar
 from pydantic_settings import BaseSettings
 
 BASE_DIR = Path(__file__).resolve().parent.parent.parent
@@ -9,8 +10,9 @@ class Settings(BaseSettings):
     API_V1_STR: str = "/api/v1"
 
     # Database
-    DB_DIR = BASE_DIR.parent / "storage" / "db"
+    DB_DIR: ClassVar[Path] = BASE_DIR.parent / "storage" / "db"
     DB_DIR.mkdir(parents=True, exist_ok=True)
+
     SQLALCHEMY_DATABASE_URL: str = f"sqlite:///{DB_DIR}/db.sqlite"
 
 

app/db/base.py

@@ -1,2 +1,3 @@
 # Import all models here for Alembic to detect
+from app.db.session import Base
 from app.models.todo import Todo